Yesterday I was wondering about what the precise set of terminology surrounding direct and nonstop flights was.

I found our previous question that covered those two main terms in detail.

But I don't feel it covered every possibility with certain kinds of stops, such as refuelling where nobody boards or gets off. I believe these are called "technical stops". I do not know if they are the only category of technical stop.

Mark provided an answer to that question that relied on another term, "leg":

  • Flight/Direct flight = One or more legs, on the same airline, in which each leg has the same flight number
  • Non-stop flight = A flight with only one leg

But it does not tell us the technical meaning of "leg".

Is a "leg" a portion between any take off and any landing, or is it a portion between one "non-technical stop" and another "non-technical stop"?

If the term "leg" ignores any intermediate refuelling stops etc, what is the technical term that would be used to cover each of those two portions of flight?

  • Related: aviation.stackexchange.com/questions/5185/…
    – JonathanReez
    Commented Sep 18, 2016 at 13:36
  • From the link above it seems that the right term is pressurization cycle, rather than leg.
    – JonathanReez
    Commented Sep 18, 2016 at 13:37
  • @JonathanReez: That seems more like an aviation term than a.... umm "travel" term. I mean something mechanics and pilots might use but not say travel agents. But maybe travel agents and such have no need for such a term? Commented Sep 18, 2016 at 15:26
  • @JonathanReez: Since segment has come up as often interchangeable with leg, does ICAO provide an official definition of segment? Commented Sep 19, 2016 at 0:55

3 Answers 3


In general travel usage a "leg" is a transport section, for flights it would be one flight (take off to landing), for a land connection (train, bus) it would be from boarding until you disembark, for a cruise (or ferry) it would be port to port.

  • 2
    But how would technical stops influence that? (That is the main point of this question.)
    – Willeke
    Commented Sep 18, 2016 at 7:34
  • 2
    A technical stop would end one leg (when the plane landed) and start a new one (when the plane left) ... as I said leg = one flight take off to landing.
    – user13044
    Commented Sep 18, 2016 at 7:36
  • 1
    So for a bus, a leg is from boarding until you disembark (what about food/bathroom/smoke breaks where you can optionally get off?), but for a flight, a leg is broken when there's a technical stop, even though nobody can disembark there? Commented Sep 18, 2016 at 7:46
  • 2
    I didn't write the rules, I simply answered based on how it is generally used in the travel industry.
    – user13044
    Commented Sep 18, 2016 at 7:57
  • 2
    Don't now how to link to what I have learned and absorbed after 30+ years working in travel.
    – user13044
    Commented Sep 18, 2016 at 8:05

So, there's really no 'one true' dictionary. Terms are used differently by different people, airlines apps and situations. Like other contributors, I'm answering based on what I've learned in and out of the industry.

In air travel, a 'leg' is a defined piece of the passengers journey. The problem is the exact meaning can change with context. So, a Travel Agent might say, the first leg of you trip is from JFK to NRT. That there might be a technical stop in ANC but that is not really relevant. If you're on the aircraft and the flight attendant says "this leg of the trip is 6.5 hours" they are referring to the JFK-ANC flight.

Further complicating this is the overlapping term 'segment' which at some point way back mostly referred to one leg of a direct flight. The two are often used interchangeably now.

Then of course, you will hear 'flight' very often used to refer to what ever it takes to fly from one place to another.

For whatever reason, I actually would not use 'leg' in the examples you provide. I would say "This flight has two segments. We have to stop in Anchorage for fuel." But, others might say something completely different.

In casual speak, 'leg' can really refer to anything. "The first leg of our trip is by train, then we fly to Dublin."

You will find the terms:

  • leg
  • flight
  • segment
  • departure
  • stage

mashed up in collections called

  • flights
  • itineraries
  • routings
  • sequences
  • lines.

There's also a bunch of other more technical terms used by specific groups or apps within the airline.


To see how the term "leg" is useful (and used), consider flight numbers.

It is typically the case (at least in US domestic flights; probably everywhere) that an airline's "flight", i.e. what an airline identifies with a flight number, actually takes off and lands at several airports consecutively on the same day - say, from airport A to B to C to D. So going from B to C is not, in that sense, a flight, but a flight leg (or flight segment).

  • 2
    Leg is not the same as segment, at least as far as IATA and the industry define it. "Segment" is synonymous on any booking system with a "flight" (so a single segment may have potentially several legs, e.g., QF 1 from Sydney to London via Dubai). (IATA actually defines a segment as from boarding to alighting, so if there is an aircraft change during the flight, then it becomes multiple segments, but I don't think any computer reservation system worries about that distinction.)
    – Calchas
    Commented Nov 29, 2017 at 19:13

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